Novel arched gemstone and method of manufacture

ABSTRACT

A diamond, which has a step-cut arched configuration on one end and a baguette-style configuration on the other, comprising a girdle, a top or crown above the girdle, and a pavilion or base below the girdle. The crown terminates in an upper planar surface known as a “table,” which is generally parallel to the girdle plane. The arched end is comprised of step-cut crown facets that are preferably arranged about a common center, and upstanding pavilion facets that are also preferably arcuately arranged about the common center. The pavilion also includes a large, arched window facet.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation in part of co-pending application Ser. No. 29/479,666 filed Jan. 17, 2014. Applicant claims priority thereto, the entire teachings of which being incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to the art of transforming rough gemstones into faceted, arched products, and, more particularly, relates to a novel arched gemstone and method for cutting and faceting gemstones in such a way as to form an arched shape having brilliance, fire and high yield that is significantly increased over prior arched gemstones.

2. Description of the Prior Art

The art of creating facets on gemstones has existed for many centuries. The first known attempt to facet a diamond is believed to have taken place in the eleventh century. At that time, eight triangular faces were polished in a rough diamond, creating what became known as the “point cut,” which resembled a pair of pyramids joined at their bases.

In the early part of the fourteenth century, a single, horizontal planar facet was introduced, which became known as the “table,” leaving four natural beveled surfaces (crown facets) that created the crown. Later, additional crown facets were added, and the shape of the table, and hence the resulting stone, was changed into different shapes. One of those shapes is the so-called “arch cut,” where one end of the table is curved and the other end generally flat like a baguette.

Currently, precious stones are first cut into a top or crown, and a bottom, base or pavilion, leaving a girdle lying between the two in a horizontal plane. Customarily, any number of top primary facets are cut into the top section, and any number of bottom primary facets are cut into the bottom. This phase of the cutting process is known as “blocking” Thereafter, additional facets may be added (depending upon the particular cut style being applied) to the top and bottom sections in a second phase known as brillianteering. “Blocking” is the step in the diamond cutting process in which the initial angles and primary facets are created from the rough stone, and “brillianteering” is the subsequent step during which secondary or minor facets are polished into the stone.

One cut style is known as the “baguette,” in which numerous facets arranged parallel to the girdle are used. The cuts are called “step-cuts” rather than brillianteering cuts because they form small “steps” in the surface of the stone as the angle of the stone surfaces is changed from facet to facet.

No matter the cut, aside from desired visual attributes of stones, weight retention is extremely important.

Rectangular cut stones can retain between 60%-75% of the weight of the rough. Therefore, such cuts are highly desirable as they result in the highest yield of all of the various cuts. In contrast, for round cuts, 40% weight retention is the accepted maximum, and 50% weight retention is standard for oval cuts. Therefore, baguette faceting is a desirable way to achieve good weight retention.

Today's diamond consumer is typically a highly discriminating and well educated shopper, looking for the highest value out of his or her investment. At the same time, the diamond supplier wants to obtain the highest yield from a given piece of rough. Since the price per carat increases exponentially in proportion to the carat weight of a particular stone, it is highly desirable to increase the yield, and conversely decrease the waste, from a given rough.

In addition, the unusual appearance of an arch shaped gemstone adds to its appeal. The particular ornamental design of a given stone, therefore, can affect the value of it and products to which it is applied as well.

SUMMARY OF THE INVENTION

It is, therefore, a principle object of this invention to provide arched gemstones, including but not limited to diamonds, which exhibit acceptable visual properties while yielding greater weight retention out of a given parcel of rough.

It is another object of this invention to provide an arch shaped gemstone that is visually attractive and unlike any other that has been proposed heretofore.

In accordance with these and other objects, the invention is directed to an arched stone that has a substantially higher yield than has heretofore been achieved while retaining optimal visual performance and appearance due to the arrangement of facets on the stones.

In general, the product of the preferred embodiment is comprised of a diamond, which has a step-cut arched configuration on one end and a baguette-style configuration on the other, comprising a girdle, a top or crown above the girdle, and a pavilion or base below the girdle. For purposes of this description, the girdle will be deemed to lie in a horizontal plane (“girdle plane”). The crown terminates in an upper planar surface known as a “table,” which is generally parallel to the girdle plane. The pavilion preferably ends at its lower most end with a keel-style culet, although any bottom contour could be employed without departing from the spirit of the invention.

In one embodiment, the pavilion is comprised of a series of step cut facets on a first, arched, end and a rectangular, baguette-style end opposite the arched end. In the preferred embodiment, the stone may be divided into twelve main top facets and ten main bottom facets as a result of the blocking step, which will be discussed in more detail below.

The resulting visual performance of the stone configured as described herein is surprising and striking, while at the same time resulting in a higher yield for a given quantity of rough material from which the stone is cut.

The technique disclosed herein results in a product which is completely unexpected and dramatically superior to what conventional wisdom in the field would predict.

Also, the particular shape chosen for the preferred embodiment of this invention has unique visual characteristics that will appeal to a wide audience.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top plan view of an arched gemstone faceted in accordance with this invention.

FIG. 2 is a bottom plan view thereof.

FIG. 3 is a front elevational view thereof

FIG. 4 is a rear elevational view thereof.

FIG. 5 is a left side elevational view thereof, which is a mirror image of the right side.

FIG. 6 is a right front top perspective view thereof.

FIG. 7 is a perspective view of a bangle to which are attached a series of arched diamonds as disclosed herein.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The instant invention, in its preferred embodiment, is directed to a shape of a cut precious stone characterized as having rectangular baguette-like features on one end, and multiple facets on the other end to form an arch shape. In creating the arch, a large “window” sized pavilion facet is employed to create the appearance one would expect to see when looking through an archway. In the preferred embodiment, the arch is formed using step cuts.

Throughout this description, the stone 10 will be referred to as a “diamond,” although any stone may be cut in accordance with this specification and, thereby, fall within the scope of the invention.

In its preferred form, diamond 10 is comprised of a top or crown section 12, and a base or pavilion section 14. The crown 12 defines a flat, planar, table 16, while the base terminates at culet 20. Culet 20 may be keel-shaped as shown. Alternatively, as mentioned above, the base may terminate without the use of a culet if desired, although the use of a culet enhances the visual performance of the stone. Diamond 10, as best seen in FIG. 1, may be thought of as being comprised of a first end portion 23 defined by width and length dimensions “X_(W)” and “X_(L)” respectively, which first end 23 in its most basic sense is comprised of a square baguette cut between first end girdle line 19 and reference line 25. It is to be appreciated, however, that the width X_(W) and length X_(L) dimensions, respectively, of the first end 23 of diamond 10 need not be the same while still falling within the scope of the invention. In the preferred embodiment, length dimension X_(L) is approximately 99°-101° of the width dimension X_(W).

Reference line 25 passes through the center of curvature C of the second, arch shaped, portion 21 of diamond 10. The overall length of the stone of the preferred embodiment is approximately 144%-151% of the width dimension X_(W). The height “Y” of the second end 19 of diamond 10 is, in the preferred embodiment, between 45% and 50% of width dimension “X_(W)” of first end 23. These parameters have been found to create the preferred visual effect, but may be varied as will be appreciated by one of ordinary skill in the art after having had the benefit of this disclosure.

In cutting diamond 10 from rough, the bottom portion of the stone is created by blocking a series of step cut facets 40, 42, 44 and 46; 50, 52, 54 and 56; 60, 62, 64 and 66; and 70, 72, 74 and 76. In addition, a crown is initially formed by blocking a series of crown facets 80, 82 and 84; 90, 92 and 94; 100, 102 and 104; and 120-140.

In addition, upstanding pavilion facets 150-165 are created in the second, arched, end of stone 10 to form a faceted, lustrous, arch around an upper boundary 27 of a “first” arched, or second, end window facet 22. Window facet 22 in the preferred embodiment is characterized as forming an enlarged window defined at least in part by an arcuate upper rib line 32, said upper rib line 32 being bounded above by said one or more upstanding pavilion facets 150-165 and below by a rib line separating window facet 22 from the “second” second-end pavilion pavilion pavilion facet 72. Facets 150-165 may be arranged at approximately the angles shown in FIGS. 3, 5 and 6 relative to the girdle plane or otherwise depending upon the visual affect desired, and may, in the preferred embodiment, be essentially a continuation of girdle 18. In the embodiment shown, facets 150-165 are oriented at approximately 90° relative to the girdle plane, and are of staggered heights arranged symmetrically about opposite sides of the pavilion of the second end 21 of diamond 10. Moreover, in the embodiment shown, facets 150-165 are arranged arcuately about common center C.

Rib line “B” between window facet 22 and second second-end pavilion facet 72 is parallel to first-end girdle edge 19, as are all of the rib lines between second-end pavilion facets 72, 74 and 76.

The crown height is the distance “A” from the girdle 18 to the table 16. The pavilion height is the distance “C” from the girdle 18 to the culet 20. The thickness of girdle 18 is depicted by the variable “B.” The crown break angle, which is an angle between the row of crown facets immediately adjacent the girdle and the girdle plane, is preferably between 40° and 43°.

In the preferred embodiment, the arch shape is formed, as discussed above, by making a series of step cuts to yield the shape shown in the drawings. It is to be understood, however, that brilliantering or other faceting cuts or polishings may be made in addition to, or in lieu of, the step cuts shown in the drawings. In addition, more or fewer step (and/or brilliantering) cuts may be made to result in an overall arch-shaped stone in accordance with this invention. It is also to be understood that the dimensional ratios and size ranges may vary for any arched stone cut in accordance with this invention, without departing from the scope of this invention, the specific dimensions shown being consistent only with the preferred embodiment.

In the preferred embodiment, the table width “Z” relative to the overall width “X” of the first end 23 of diamond 10 is between 60% and 72%. Also, the crown height “A” is preferably 10.5% to 13.5% of the overall height of stone 10, which overall height is the accumulation of dimensions “A,” “B” and “C,” as best seen in FIG. 4. In addition, in the preferred embodiment, height “D” of window 22 in pavilion 14 is preferably between 2% and 24% of the overall height of stone 10.

Girdle height “B” is preferably between 2%-4% of the overall height of stone 10. Base or pavilion height “C” is preferably between 50% and 55% of the overall height of the stone.

The step-cut facets 80, 82 and 84; 90, 92 and 94; 100, 102 and 104; and 120-140 in crown 12 are, in the preferred embodiment, sized and oriented as shown in FIGS. 1 and 3-6.

Facets 80, 82 and 84; 90, 92 and 94; 100, 102 and 104 may be referred to as first end crown facets. Facets 80, 90 and 100 may be referred to as “first” or “a first row of” first-end crown facets, facets 82, 92 and 102 may be referred to as “second” or “second row of” first-end crown facets, and facets 84, 94 and 104 may be referred to as “third” or “third row of” first end crown facets.

The size and orientation of the facets 40, 42, 44 and 46; 50, 52, 54 and 56; 60, 62, 64 and 66; and 22, 72, 74 and 76 that make up a preferred embodiment of the pavilion in the preferred form of stone 10 are shown best in FIGS. 2 through 6.

The size and orientation of the facets 120-140 that make up the crown portion of second end 21 are best shown in FIGS. 1 and 3-6. Crown arch facets 120-140 maybe referred to as second end crown facets. Facets 120, 123, 126, 129, 132, 135 and 135 may be referred to as “first” or “first row of” second end crown facets, facets 121, 124, 127, 130, 133, 136 and 139 may be referred to as “second” or “second row of” second-end crown facets, and facets 122, 125, 128, 131, 134, 137 and 140 may be referred to herein as “third” or “third row of” second-end crown facets.

The rib lines 160, 161, 162, 163, 164, 165, 166 and 167 lying between the table and girdle which separate the crown arch facets 120-140 are themselves arranged, in the preferred embodiment, radially about center C. The first such rib line 160 is preferably oriented at an angle relative to reference line 25 of between 7° and 9°, the second such rib line 161 being oriented preferably at an angle relative to reference line 25 of between 31°-35°, the third such rib line 162 being oriented preferably at an angle relative to reference line 25 of between 53°-57°, the fourth such rib line 163 being oriented preferably at an angle relative to reference line 25 of between 75°-80°, the fifth such rib line 164 being oriented preferably at an angle relative to reference line 25 of between 100°-104°, the sixth such rib line 165 being oriented preferably at an angle relative to reference line 25 of between 123°-127°, the seventh such rib line 166 being oriented preferably at an angle relative to reference line 25 of between 145°-149°, and the eighth such rib line 167 being oriented preferably at an angle relative to reference line 25 of between 169°-173° (all relative to center C). It is to be understood that different angles, and different numbers and sizes of crown arch facets, may be used while staying within the scope of the invention.

The preferred range of break angles of the first row of crown arch, or second-end crown, facets 120, 123, 126, 129, 132, 135 and 135 (as well as first end crown facets 80, 90 and 100) is, as stated previously, between 40°-43°. The preferred range of angles of the second row of crown arch, or second-end crown, facets 121, 124, 127, 130, 133, 136 and 139 (as well as first end crown facets 82, 92 and 102) relative to the girdle plane is 30°-32°. The preferred range of angles of the third row of crown arch, or second-end crown, facets 122, 125, 128, 131, 134, 137 and 140 (as well as first end crown facets 84, 94 and 104) relative to the girdle plane is 20°-22°

In the preferred embodiment, the pavilion break angle, which is the angle between the girdle plane and the first row of pavilion facets 22, 40, 50 and 60 immediately adjacent the girdle, is 50°-55°, and this first row of facets occupy in the range of 16%-18% of the width X_(W) of diamond 10. The second row of pavilion facets 42, 52, 62 and 72 are oriented at an angle relative to the girdle plane preferably in the range of 42°-45°, and occupy in the range of 10%-12% of the width X_(W). The third row of pavilion facets 44, 54, 64 and 74 are oriented at an angle relative to the girdle plane preferably in the range of 36°-39°, and occupy in the range of 9%-11% of the width X_(W). The fourth row of pavilion facets 46, 56, 66 and 76 are oriented at an angle relative to the girdle plane preferably in the range of 30°-32°, and occupy in the range of 7%-9% of the width X_(W).

The first row of pavilion facets 40, 50 and 60 in the first end of diamond 10 may be referred to as “first” or “first row of” first-end pavilion facets, the second row of pavilion facets 42, 52 and 62 in the first end of diamond 10 may be referred to as “second” or “second row of” first-end pavilion facets, the third row of pavilion facets 44, 54 and 64 may be referred to as “third” or “third row of” first-end pavilion facets, and the fourth row of pavilion facets 46, 56 and 66 may be referred to as “fourth” or “fourth row of” first-end pavilion facets.

Likewise, first pavilion facet 22 may be referred to as the “first” second-end pavilion facet, facet 72 as the “second” second-end pavilion facet, facet 74 as the “third” second-end pavilion facet, and facet 74 as the “fourth” second-end pavilion facet.

Stones cut in accordance with the invention may be used in jewelry pieces or as standalone gems. An example of one such jewelry piece is shown in FIG. 7, in which a series of arch shaped stones are arranged in correspondingly shaped arches in a bracelet, ring, earring, pendant or the like. The combination of arched stones and corresponding arches creates a stunning, unusual and unexpected visual effect.

As specified in connection with all embodiments, the sequence of cuts made during the blocking phase is irrelevant, so long as the resulting diamond has the arrangement of facets within the specified ranges as contemplated by the invention. For example, the main pavilion facets may be cut first, or the main crown facets may be cut first. However, the actual sequence of blocking steps will be selected by the cutter based on such parameters as the shape and grain structure of the rough diamond.

While the invention has been described in its preferred form or embodiment with some degree of particularity, it is understood that this description has been given only by way of example and that numerous changes in the details of construction, fabrication, and use, including the combination and arrangement of features, may be made without departing from the spirit and scope of the invention. 

What is claimed is:
 1. An arched diamond, comprising: a generally planar table lying in a table plane; a circumferential girdle lying in a girdle plane, the table plane being substantially parallel to the girdle plane; a first end of the diamond being substantially square and including a first-end crown section defined by first, second and third parallel step-cut crown facets lying between the table and girdle; a second, arched, end of the diamond being arched shaped and including a crown section defined by a series of angularly arranged step-cut facets arranged radially about a common center; the first end of the diamond including a first-end pavilion section, lying between the girdle and a culet, defined by first, second, third and fourth rows of step cut first-end pavilion facets forming, together with the first end crown section, a baguette style end; the second end of the diamond including a second-end pavilion section, lying between the girdle and the culet, comprised of: first, second, third and fourth step cut second-end pavilion facets, and one or more upstanding pavilion facets arranged in an arcuate manner about said common center; the first second-end pavilion facet being characterized as forming an enlarged window defined at least in part by an arcuate upper rib line, said upper rib line being bounded above by said one or more upstanding pavilion facets and below by the first second-end pavilion facet.
 2. The diamond of claim 1, wherein the upstanding pavilion facets are oriented at substantially 90° relative to the girdle plane and arranged in an arch having a substantially common center.
 3. The diamond of claim 1, wherein the first second-end pavilion facet is oriented at a break angle of approximately in the range of 50°-55° relative to the girdle plane.
 4. The diamond of claim 1, wherein the first row of crown facets on the first end of the diamond are oriented at an angle of 40°-43° relative to the girdle plane.
 5. The diamond of claim 1, wherein the second row of crown facets on the first end of the diamond are oriented at an angle of 30°-32° relative to the girdle plane.
 6. The diamond of claim 1, wherein the third row of crown facets on the first end of the diamond are oriented at an angle of 20°-22° relative to the girdle plane.
 7. The diamond of claim 1, wherein the second second-end pavilion facet is oriented at an angle of approximately in the range of 42°-45° relative to the girdle plane.
 8. The diamond of claim 1, wherein the third second-end pavilion facet is oriented at an angle of approximately in the range of 36°-39° relative to the girdle plane.
 9. The diamond of claim 1, wherein the fourth second-end pavilion facet is oriented at an angle of approximately in the range of 30°-32° relative to the girdle plane.
 10. The diamond of claim 1, wherein the first row of pavilion facets on the first end of the diamond is oriented at a break angle of approximately in the range of 50°-55° relative to the girdle plane.
 11. The diamond of claim 1, wherein the second row of pavilion facets on the first end of the diamond is oriented at an angle of approximately in the range of 42°-45° relative to the girdle plane.
 12. The diamond of claim 1, wherein the third row of pavilion facets on the first end of the diamond is oriented at an angle of approximately in the range of 36°-39° relative to the girdle plane.
 13. The diamond of claim 1, wherein the fourth row of pavilion facets on the first end of the diamond is oriented at an angle of approximately in the range of 30°-32° relative to the girdle plane.
 14. The diamond of claim 1, wherein the first row of crown facets on the second end of the diamond are oriented at an angle of 40°-43° relative to the girdle plane.
 15. The diamond of claim 1, wherein the second row of crown facets on the second end of the diamond are oriented at an angle of 30°-32° relative to the girdle plane.
 16. The diamond of claim 1, wherein the third row of crown facets on the second end of the diamond are oriented at an angle of 20°-22° relative to the girdle plane.
 17. An arched diamond, comprising: a table lying in a table plane; a girdle lying in a girdle plane, the girdle plane being substantially parallel to the table plane; the diamond being comprised of a first end and a second end; the first end being comprised of a first-end crown section and a first-end pavilion section; the second end being comprised of a second-end crown section and a second-end pavilion section; the first-end crown section being comprised of: a portion of the table, and first, second and third rows of first end step-cut crown facets, the first row being oriented at a first break angle relative to the girdle plane and being arranged along a rectangular periphery of the first end of the diamond, the second row being oriented at a second break angle relative to the girdle plane, and the third row being oriented at a third break angle relative to the girdle plane; the first end pavilion section being comprised of: first, second, third and fourth rows of first end step-cut crown facets, the first row being oriented at a first break angle relative to the girdle plane and being arranged along a rectangular periphery of the first end of the diamond, the second row being oriented at a second break angle relative to the girdle plane, the third row being oriented at a second break angle relative to the girdle plane, and the fourth row being oriented at a fourth break angle relative to the girdle plane; the second-end crown section being comprised of: a continuation of the table, and a series of angularly arranged step-cut facets arranged radially about a common center; the second-end pavilion section being comprised of: first, second, third and fourth step cut second-end pavilion facets, and one or more upstanding pavilion facets being arranged in an arcuate relationship about said common center; the first second-end pavilion facet being characterized as forming an enlarged window defined at least in part by an arcuate upper rib line, said upper rib line being bounded above by said one or more upstanding pavilion facets and below by the first second-end pavilion facet.
 18. The diamond of claim 17, wherein the upstanding pavilion facets are oriented at substantially 90° relative to the girdle plane and arranged in an arch having a substantially common center.
 19. The diamond of claim 17, wherein the first second-end pavilion facet is oriented at a break angle approximately in the range of 50°-55° relative to the girdle plane.
 20. The diamond of claim 17, wherein the first row of crown facets on the first end of the diamond are oriented at an angle approximately in the range of 40°-43° relative to the girdle plane.
 21. The diamond of claim 17, wherein the second row of crown facets on the first end of the diamond are oriented at an angle approximately in the range of 30°-32° relative to the girdle plane.
 22. The diamond of claim 17, wherein the third row of crown facets on the first end of the diamond are oriented at an angle approximately in the range of 20°-22° relative to the girdle plane.
 23. The diamond of claim 17, wherein the second second-end pavilion facet is oriented at an angle approximately in the range of 42°-45° relative to the girdle plane.
 24. The diamond of claim 17, wherein the third second-end pavilion facet is oriented at an angle approximately in the range of 36°-39° relative to the girdle plane.
 25. The diamond of claim 17, wherein the fourth second-end pavilion facet is oriented at an angle approximately in the range of 30°-32° relative to the girdle plane.
 26. The diamond of claim 17, wherein the first row of pavilion facets on the first end of the diamond is oriented at a break angle approximately in the range of 50°-55° relative to the girdle plane.
 27. The diamond of claim 17, wherein the second row of pavilion facets on the first end of the diamond is oriented at an angle approximately in the range of 42°-45° relative to the girdle plane.
 28. The diamond of claim 17, wherein the third row of pavilion facets on the first end of the diamond is oriented at an angle approximately in the range of 36°-39° relative to the girdle plane.
 29. The diamond of claim 17, wherein the fourth row of pavilion facets on the first end of the diamond is oriented at an angle approximately in the range of 30°-32° relative to the girdle plane.
 30. The diamond of claim 17, wherein the first row of crown facets on the second end of the diamond are oriented at an angle approximately in the range of 40°-43° relative to the girdle plane.
 31. The diamond of claim 17, wherein the second row of crown facets on the second end of the diamond are oriented at an angle approximately in the range of 30°-32° relative to the girdle plane.
 32. The diamond of claim 17, wherein the third row of crown facets on the second end of the diamond are oriented at an angle approximately in the range of 20°-22° relative to the girdle plane. 